[ATM] Re: Aero Ektar Coma Corrector?

["M/S Heald" <maheald@octa4.net.au>]

Hello! I have a 178mm aero ektar that I have to stop down from f2.5 to

f5.6 because of coma before getting sharp 4x5 wide field shots. Is it 

possible to design a coma corrector so that I can use it at f4 or 

f2.5? Best regards.

> 

Do you have the prescription or some other information about the original
lens?

 

 

No, I'd have to do some research to see if its available.  I imagine I'd
have to reduce the info from actual photographs, though.

 

The reason I am curious is that most 4x5 lenses are f5.6, with an occasional
one thrown in at f4 - nothing at f2.5.  Even purchasing a new lens at f4.0
or f5.6 would not guarantee that it would not need to be stopped down to
become sharp.  F5.6 would likely be too slow to use filters for B&W as well.
Color emulsions are a problem in 4x5 as well.

 

It may not be worth the effort to try and make a coma corrector, but it
might be an interesting project, and if it were to pan out, make one heck of
a wide field lens and open up a lot of imaging options.

 

Best regards.

 

Mike

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